Power lift mechanism for tractors



March 1; 1938. E. A. JOHNSTON 2, ,6

' POWER LIFT MECHANISM FOR "IRACTORS 4 Sheets-Sheet 1 Filed March 24, 1937 @N ow Invenfi i' Ed armwmswn I E. A. JOHNSTON .POWER LIFT MECHANISM FpR- TRACTORS March 1,1938.

4 sheets-sheet 2 Filed Mafch 24, 19:57

March 1, 1938. E. A. JOHNSTON I POWER LIFT MECHANISM FOR TRACTORS Fil edMarch 24, 1937 4 Sheets- Sheet 5- March 1, 1938 E A. JOHNSTON POWER LIFT MECHANISM FOR TRACTORS Fiied March 34, 1937 4 sheets -sheefi 4 Patented Mar. 1,

' Edward Johnston, Chicago, Ill., assignor to International Harvester Company, a corporation of NewJersey Application March 24, 1

' 12 Claims.

Thisgnvention relates to a power lift mechanism for tractors. More particularly it relates to a' 'mechanical device adapted to be operated by the engine power of a tractor for lifting and lowering an implement connected to the tractor.

A principal object of the invention is the construction of a power lift mechanism having an automatic partial revolution power disconnecting means and a positive lock in any power disconnected position.

Another principal-object is the provision in a partial revolution power lift device of a construction in which the speed reduction is between the power disconnecting means and the lifting shaft, whereby much smaller and .cheaper parts may be utilized. Another object is the adaptation of a planetary gear reduction to a power lift device for obtain- .ing a simple large ratio reduction with a minimum of friction loss. a

.Another object is the provision of a simplified chain drive taken from a .cross transmission shaft.

of the tractor.

. olution or may consist of several partial revolutions of a diiferentnumber of degrees.

The above objects and others, which will be apparent from the detailed description to follow,

are accomplished by'a'mechanism in which a continuously rotating member isdriven from a shaft operated by the tractor engine. This'memher is rotatabiy mounted on a transverse lifting shaft to simplify the construction of the. device andto make possible a lifting shaft extending transversely to each side of the'tractor. A sec-' ond member: rotatably mounted on the liftin shaft, carries a latch'gmechanism engageable with the continuously rotating member for transmitting power to a particular type of gear reduction mechanism. The gear" reduction mechanism, il-

lustrated in the drawings, consists of a statlonary internal gear: a movable internal gearand a planetary pinion gear carried by the d1sen-' gageablepower transmitting member. By means of a slight variation in the number of teeth in thetwo internal gears, a large gear reduction may be simply and satisfactorily obtained. The

937, Serial No. 132,672

F u e l is a side elevation of the rear portion a .of a tractor with'one of the rear wheels removed showing a representative installation of a power lift mechanism construction according to the invention; 5

Figure 'fis a plan view of the structure shown in Figure 1;

.Figure 3 is a transverse section taken on the Figure 3; l v Figure 6 is. the same section as Figure 3 of the 16 casing containing the power lift mechanism with the internal mechanism shown in elevation;

. Figure 'l is a section taken on the line .-1 --l of Figure 6; and;

Figure 8 is a top plan .view the power lift casing with a portion of the top at one end broken away to show the drive mechanism in plan view.

A power'lift mechanism incorporatingthe in-' vention has .been shown on a. tractor with an attached implement in Figures 1 and 2 to illustrate the application of such a mechanism to a .tracton- The'tractor, as illustrated, has side frame members I0, a-rear transmission and final drive housing ll, laterally extending axle housings l2and drive wheels l3 mounted on the axles. 30. v

A clutchhousing I4 is also illustrated from which power is transmitted to the transmission by suitable means enclosed by a tunnel IS. A gasoline 'tank' i6 is shown supportedon brackets II. A

steering wheel l8 and an operator's seat I! are shown .at the proper locations on the tractor. I

At the rear of the tractor 'a frame'stru'cture 20 provides means for mounting implement supporting beams 2| and a transverse rockshaft 22. Said rockshaft is connected to a transverse im- .40.

.plement supporting bar 23 carried by the beams 2| by means of spring pressed links 23. Shanks 23 connected to the bar 23 illustrate means for carrying earth working implements.

to a bracket 21' mounted on the bar .23; The 4 movable planetary gear is rigidly secured to the.

lifting shaft. A control mechanism is provided-- for engaging and disengagingthe' ratchet drive lifting lever 25 is also connected by a link it with a crank 23 fixed on a lifting shaft 33, whichformsthe output shaft of the power lift mechanism to 50 be hereinafter described.

As a support for the lifting mechanism, a transverse member 3| extends transversely of the tractor being mounted on the side frame members The rockshaft 22 carries rigidly therewith a lifting lever 25, which is connected by a link 23,

tunnel l5. On its flat upper side, the power lift casing 32 is rigidly secured by any suitable means. as best illustrated in Figures 4 and 5.

Referring to these figures, a transverse vertical sheet metal member 33, mounted on the trans? mission casing below the gasoline tank l6, forms a means for mounting the casing 32 in a concealed position beneath the gasoline tank and in a. location where it does not form an inconvenience to the operator or obstruct his vision. An extension 34 of the power lift casing extends rearwardly and over one of the flanges of the member 33, being rigidly secured to the casing H by a cap screw. This extension rigidly secures the power lift casing in position and takes the torque in both directions developed by operation of the lifting shaft 33. v

In a tractor of the type disclosed, the transmission mechanism includes a transverse shaft 35, illustrated at the-broken away section in Figure 3. To provide .means for driving the power lift mechanism, the bearing support, normally used in the casing at one end of the shaft, is removed and a special bearing support 33 is substituted.

Said support includes means for retaining a ball.

'44. The flange 44 is integrally with a sleeve-45 slidably and non-rotatably mounted on the shaft 33. Adjustable spring pressure means maintain the two clutch faces in engagement duringnormal operation and provide an over-load release.

A cupped cover 46 is secured to 'a casing 41.

Said casing is secured to thebearing support 36 to form an enclosure for the drive sprocket and its associated parts. The casing 41 is provided with an upward extension 48 open to provide for an upwardly extending drive chain 43, which surrounds the sprocket "and provides means for driving a chain sprocket '50, rotatably mounted on the shaft 33.

The chain sprocket 53 is splined on a sleeve 5| rotatably mounted on the shaft 38. The open end of the main casing 32 is'closed by a cover member 52, which is formed with a bearing portion 52' for one end of the lifting shaft 33. A ball bearing assembly 53, mounted on the shaft 38, provides a bearing for one end of the rotatable assembly formed by the sprocket 53 and the sleeve 5|. A

plate member 54, set into the casing between the end thereof and the cover member 52, forms a I supporting means for a ball bearing assembly 55, which also supports the sleeve 5|.

' At the end opposite the chain sprocket, the.

The cover member 52 is provided on the under-' neath side with a hollowtubular extension 58, which-is in alignmentwith the'extension 48 on the casing 41. These two extensions form a substantially continuous housingfor the drive chain 43. A sheet metal member 53 isclamped around the two extensions, as best shown in Figure 1, to form a closed compartment. dotted lines of Figure 1, portions of the extensions may be broken away to form an inspection opening for observing the drive chain. u

Substantially midway of the casing 32, an in; wardly extending flange 63 is formed to provide an abutment for an internal gear 6|, which is positioned in the casing from the opposite end against the flange 60. The gear BI is provided with a plurality of circumferentially spaced arcuate lugs 62 which fit between corresponding lugs 63 formed around the interior of the casing adjacent the flange 60. By this means, the internal gear is held against rotation in the casing. A sleeve member 64, which provides a planetary gear carrier, is mounted within the main portion of the casing 32 on a. bearing sleeve 65 for rotation on the lifting shaft 33. Said sleeve member is provided at one end adjacent the lugs 56 with a radial extension 64'. A pivot pin 66 fixed in said extension forms a pivotal mounting for apawl or ratchet member 61. Said member is provided at one end with a roller 68 adapted to engage the notches 51 formed on one face of the lugs 56.

The other end of the pawl 61 is extended to form an abutment against which a spring 63 reacts to urge the pawl into engagement with the lugs 56.

As shown in The spring 63 is mounted on a.pin 18, fixed to the extension 64'. A stop means is formed for the other end of the spring in the form of a pin 1| fixed to the extension 64'.

The pawl or ratchet member 61 is also provided with a lateral extension 12, which carries a roller 13 positioned axially beyond the extension 65.

This roller, as will be hereinafter described, con-'- trols the throw-out and disengagement of the pawl 61.

An internal gear 14 positioned coaxially of the shaft 30 and lying adjacent the gear 6|, is formed integrally with the hub portion 15, which is rigidly keyed to the shaft 33. A cover member 16, which closes the open end of the casing 32, is formed with a bearing portion 11 for rotatably supporting one end of the shaft 30. Said cover member entirely encloses the casing at this end. The gear 14 is rigidly connected as an integral member with the hub 15. A rib 18 is formed around this structureto provide a trackfor locking roller 13. Said roller is rotatably carried on a pin rigidly mounted on a reciprocable member 8|. As illustrated, two notches 82 are formed in the gear member opening inwardly from the track rib .18 to provide two locations for seating "of the locking roller 13. As shown in Figure '7,

a substantial cuaarance is provided in the notches at each side of the roller 19.

The actuating member 8| is mounted for reciprocation in a transverse bore 8| formed in an integral extension of the casing wall. A spring pressed member 83 abuts one end of the member 8|, acting to urge the locking roller 13 into the notches' 82. -At its, other end, the member 8| is rigidly secured to.a cam' supporting member 84. Said member is provided with a bore which provides for mounting the member slidably along the sleeve 64. Around said sleeve,-radial flange 85 of'a uniform radius is formed integrally with the member 84. Said flange is in turn formed on its face. with an eccentric cam 86, as best shown in elevation in Figure 5. Said cam is adapted at its low point to be slidable under the 'roller13, carried by the pawl 61.v As the pawl carrier rotates, the roller 18 rides the cam around to a high position thereby disengaging the roller 88 from the notches 51 and allowing the'actuating member 8| to move in an axial direction. of the shaft 30, as best'shown in Figure 5, thereby seating the locking roller 19 in one of the notches 82. As soon as the roller 62 on the pawl 6! is disengaged, there is no longer any drive torq e applied to' the sleeve 64.

The sleeve member 64 carries axially aligned extensions 81 through which a .pinion shaft 88 extends. A planetary pinion' gear 89 rotatably mounted on said shaft engages the teeth'on the fixed internal gear 65 and the rotatably internal gear 14.

The actuating member 8| has a reduced end portion 90 which is engaged by a cam lever 9| carried by an operating shaft 92. Said shaft is rotatably mounted in the casing extending outside the casing for actuation by means of ahand lever 93. It will be noted that the .shaft extends through an opening provided in the transverse member 33 tobring the operating handle within reach of'the tractor operator.

Certain features of the operation of the mechanical power lift device, as above described;

have been explained in connection with the description of the parts; The complete operation will now be described in the sequence of operation.

By means of the connection with the continuously operating engine driven shaft 35', continuous rotation is applied to the chain sprocket 50 through the intermediate driving parts. The slip clutch formed between the flange 44 and the face 43 on the chain sprocket 42 provides an overload release means when a load is applied to the lifting shaft 38 with excess of a'predetermined amount.

The sprocket 50, being splined on the sleeve 5|, continuous rotation is applied to said sleeve and to the ratchetlugs 56 carried thereby. In the idle position of the lifting shaft, the actuating memberBl is in the position shown in the drawings with the locking roller 19 seated in one of the notches 82, formed in the rib 18, whereby thegear 14, its hub and the lifting shaft 30 are locked in position.

When the operator desires to rotate the shaft 30 to lift or lower the: implements connected thereto, the operating handle 93 is moved angularly to apply pressure in an axial direction against the member 8|. The spring pressure applied through the member -83 is overcome, thereby moving the locking roller 19 out of the notches 82 with which it is engaged. Simultaaxially away from the roller 13. When the support for this-roller is thereby removed, the spring -69 moves thepawl member 61 with the roller 68 into engagement with one of the notches 51. 7

This type of gear may be described as epicyclic' as well as planetary. As shown by legendson the drawings in Figure 3, the .pinion 894s formed with twelve teeth, the internal gear 8| is formed J with thirty-seven teeth, and the internal gear 14 is formed with thirty-eight teeth. With this toothconstruction, for each rotation of the sleeve member 64 thereby carrying the pinion gear shaft 88 about the shaft 30, themovable'gear l4, having one more tooth than the gear 6|,is backed up an angular distance equivalent to one tooth. By corresponding reasoning, the gear 14 is backed up one complete revolution for thirty-eight revolutions of the pinion shaft 88 as it planets around the shaft 30. This type of gearing is a simple, compact, durable and powerful means of obtain ing a high gear reduction.

After the shaft 30 has rotated a-half revolu-' tion or any other angular distance for which a corresponding notch 82 has been provided, the

of the cam 86 will be required to lift the pawl out of engagement. For that reason, the notches 82.are formed of a width greater than the diam- ,eter of the lockingv roller '|9-to allow for the movement following actuation of the member 8| and preceding disengagement of the pawl.

It will be noted that there is also a substantial reduction in speed between the drive shaft 35 and the sleeve 5| due to the sprocket 50 being of a larger diameter than the sprocket 42. This reduction together with the reduction obtained by the epicyclic gearing amounts to forming over fifty to one. It will be understood that lifting cranks may be applied to either end of the shaft 30. In Figures land 2, a lifting crank 29 is shown on one end of the shaft, being connected to a lifting link 28. 7 It will be understood that when the lift is trippedby actuation of the hand lever 93, the lifting crank 29 moves from the provision shown in Figures 1 and 2 to a position with the crank pin diametrically opposite, there by lifting the implements out of soil engaging position.

' As made clear in the description and explanaexpensive units may be utilized. At the output in power lift devices usinghalf revolution clutches- .on the power output side of a. gear reduction.

Y r It is to be understood that applicant has shown Y neously, the cam suppo i g member moved and described only a preferred embodiment of as his invention all modifications falling within the scope of the appended claims. .What is claimed is;

1'. A power lift device for tractors comprising,

in combination, a casing on the tractor, a liftmg shaft-journaled in said casing, a pinion carrierrotatably mounted in the casing, disengage able means for rotating said carrier, a planetary pinion rotatably supported on said carrier, two gears mounted in the casing concentric with respect to the pinion carrier in engagement with fixed with respect to the casing, means for se-' a curing one gear for rotation with the lifting shaft, and releasable means' for. locking the ring gear secured to the shaft in position against rotation.

whereby upon each revolution of the planet carv rier one of said gears is rotated relative to. the other, means for holding one gear-fixed with respect to the casing, means for securing one gear for rotation with the lifting shaft, and releasable means for locking the ring gear secured to the shaft in position against rotation. v

3. A power lift device for tractors comprising, in combination, a casing on the tractor, a lifting shaft journaled in said casing, a pinion carrier joumaled in the casing concentric with respect to the lifting shaft, disengageable means for rotatingsaid carrier, a planetary pinion journaled' on said carrier, a gear concentric with respect to the shaft in mesh with said pinion, a second gear concentric with respect to the shaft in mesh with said pinion, said gears having different numbers of teeth whereby upon each revolution of the pinion carrier one of said gears-is rotated relative to the other, means for fixing one gear to the casing, means for fixing one gear to the shaft, and releasable means for locking the ring gear fixed to the shaft in position against rotation.

in combination, a, casing on the tractor, a. lifting shaft journaled in said casing, a pinion carrier rotatably mounted in the casing, driving means for rotating said carrier, diseng ng means for rendering said means inoperat ve, a planetary pinionrotatably supported on said carrier, two gears mounted in the casing .concentric with'respect to e pinion carrier in engagement with the-plan tary pinion, said gears having different numbers of teeth whereby upon each revolution of the planet carrier one o f said gears is rotated relative to the other, means for holding one gear fixed with respect to the casin means for securing the other gear for rotation with the lifting shaft, releasable means for locking the gear secured tothe shaft in position against rotation, and operating connections be-' tween said releasable means and the disengag ng means operative to engage the driving means when the gear is unlocked and to disengage the driving means when the gear is locked.

5. A power lift device for a tractor having a motor comprising, in combination, a casing on the tractor, a lifting shaft :lournaled in said casing, a sleeve rotatably mounted on the lifting shaft, an internal gear fixed to the casing con centric with respect to the lifting shaft, a second internal gear fixed to the lifting shaft, a pinion rotatably carried by said sleeve on an axis parallel.

.to and spaced from the lifting shaft, said pinion meshing with each of said internal gears, said internal gears having different numbers of teeth whereby upon each revolution of the pinion carrier sleeve the second ring gear is rotated a distance depending upon the teeth variations, re-

leasable means for locking the second ring gear in position against rotation, and releasable driving means'for the sleeve operatively connected to the tractor motor.

6; A power lift device for a tractor having a 4. A power lift device for tractors comprising,,

motor comprising, in combination, a casing on the tractor, a lifting shaft journaled in said casing, a sleeve rotatably mounted on the lifting shaft, an internal gear fixed to the casing concentric with respect to the lifting shaft, a second internal gear fixed to the lifting shaft, a pinion iotatably carried by said sleeve on an axis parllel to and spaced from the lifting shaft, said inion meshing with each of said internal gears, said internal gears'having different numbers of teeth whereby upon each revolution of the pinion carrier sleeve the second ring ear is rotated a distance depending upon the teeth variations,

releasable means for locking the second ring gear in position ,against rotation, releasable driving means for the sleeve operatively connected to thetractor motor, and means operable with said lockingvmeans for controlling the driving means.

7. A power lift device for tractors comprising, in combination, acasing on the tractor, a-lifting shaft journaled in said casing, a planet gear carrier rotatably mounted on the lifting shaft, a driving sleeve rotatably mounted on the lifting shaft, means for continuously rotating said sleeve, a planetary gear rotatably carried by the planet carrier on axis'parallel to and spaced from the lifting shaft, an internal gear fixed to the casing concentric with respect to the shaft and engaged by the planetary gear, a second internal gear fixed to the lifting shaft and engaged with said planetary gear, said internal gears having different numbers of teeth whereby upon each revolution of the planet carrier the second ring gear is rotated a distance depending upon the teeth variations, releasable means for locking the second ring gearin position against rotation, and releasable driving connections between the sleeve and the planet gear carrier.

8..A power lift device for tractors comprising, in combination, a casing on t e tractor, a lifting shaft Journaled in said casing, a planet gear carrier rotatably mounted on the liftingshaft, a driving sleeve rotatably mounted on the lifting shaft, meansfor continuously rotating said sleeve, a

planetary gear rotatably carried by the planet carrier on an axis parallel to and spaced from the lifting shaft, an internal gear fixed to the casing. concentric with respect to the shaft and engaged bythe planetary gear, a second internal gear fixed to the lifting shaft and engaged with said planetary gear, said internal gears having difierent numbers of teeth whereby upon each revolution of the planet carrier the second ring gear is rotated a distance depending upon the teeth variations, releasable means for locking the sec-- ond ring gear inposition against rotation, releas able driving'connections between the sleeve and the planet gear carrier, and means operable with said locking means for actuating said connections.

9. A power lift device for tractors comprising,

in combination, a casing on the tractor, a lifting shaft journaled insaid casing, a sleeve rotatably I revolution of the pinion carrier sleeve, the'second ring gear is rotated a distance depending upon the teeth variations. and releasable means for locking the second ring gear in position against rotation.

10. A power lift device for tractors comprising,

in combination, a casing on the tractor, a lifting shaft journaled in said casing, a sleeve rotatably mounted on the lifting shaft, disengageable means for rotating said sleeve, a pinion rotatably carried by said sleeve, a gear fixed to the casing concentric with respect to the shaft and'engaged by the pinion, a second gear fixed to the lifting shaft and engaged with said pinion, said gears having different numbers of teeth whereby upon each revolution of the pinion carrier sleeve the second ring gear is rotated a distance depending upon the teeth variations, releasable means for locking the second ring gear in position against rotation, and means operable with said locking means for disengaging and engaging the sleeve driving 7 means.

' tor, a pinion carrier sleeve rotatably mounted on the lifting shaft and provided with a radial extension adjacent the end of the first mentioned sleeve, a ratchet member pivoted on said extension on an axis parallel to the axis of the lifting shaft, said member having a roller latch movable with the member toward and away from the first mentioned sleeve, a plurality of projections formed on the first mentioned sleeve providing notches engageable by the ratchet member, spring means for urging said ratchet member toward the notches, a cam member mounted eccentrically with respect to the second mentioned sleeve and being axially movable with respect thereto, said ratchet member being formed with a portion engageable with the cam to control engagement of the ratchet member, a pinion rotatably carried by the second sleeve on an axis parallel to and spaced from the lifting shaft, an internal ring gear fixed to the casing and engaged by the pinion, a second internal ring gear carried by the lifting shaft in mesh with said pinion, said internal gear having different numbers of teeth whereby upon each revolution of the pinion carrier sleeve the second ring gear is rotated a distance depending upon the tooth variations, said second ring gear being formed with circumferentially spaced notches, a releasable locking member engageable with said notches, said member being secured to the cam whereby the cam is moved to throw the ratchet into and out of driving position with the locking and unlocking of the gear.

12. A power lift device for tractors comprising, in combination with an engine driven shaft projecting laterally from the tractor, a casing mounted on the tractor frame extending transversely thereof forwardly of said power shaft, a lifting shaft journaled in said casing and extending lat-' erally beyond each end thereof, a chain sprocket rotatably mounted on said lifting shaft within the casing, a chain sprocket mounted on the power shaft, a drive chain connecting said sprockets, a sleeve rotatably mounted on the lifting shaft and secured for rotation with the sprocket, a pinion carrier sleeve rotatably mounted on the lifting shaft and provided with a'radial extension adjacent the'end of the first mentioned sleeve, a ratchet member pivoted on said extension on an axis parallel to the axis of the lifting shaft, said member having a roller latch movable with the member toward and away from the first mentioned sleeve, a plurality of projections formed on the first mentioned sleeve providing notches engageable by the ratchet member, spring means for' urging said ratchet member toward the notches. a cam member mounted eccentricaily with respect to the second mentioned sleeve and being axially movable with respect thereto, said ratchet member being formed withta portion en gageable with the cam to control engagement of tance-depending upon the tooth variations, said second ring gear being formed with circumferentially spaced notches, areleasable locking member engageable with saidnotches, said member being secured to the cam whereby the cam is moved to throw the ratchet into and out of driving position with the locking and unlocking of the ear,

A. JOHNB'IUN. 5o 

